Expand Configuration and Management Manual (H06.21+, J06.10+)

Configuring Expand-Over-IP Lines
Expand Configuration and Management Manual — 529522-013
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Local Area Network (LAN) Driver and Interrupt
Handlers (DIHs)
greater bandwidth and fault tolerance. However, all elements, including the network
itself, must have redundancy to obtain full benefit of the configurations.
The decision of which adapter (or CLIM) and path to apply for a particular Expand
connection in conventional NonStop TCP/IP, CIP, and LNP-configured NonStop
TCP/IPv6 is made explicitly by how you configure the adapters (or CLIMs), NonStop
TCP/IP processes, and lines. This selection is independent of the external network.
The adapters and lines are applied in parallel, but if there is no redundancy in the
network to which they connect, the effectiveness of the parallelism is considerably
reduced. In these cases, the fault-tolerance decisions made in Expand for multi-line IP
paths can be disruptive rather than helpful.
NonStop TCP/IPv6 configured without LNP and CIP using the default (all interface)
PROVIDER makes a dynamic choice of which adapter (or CLIM) and line to use,
among any configured redundant assortment, based on the destination address of the
IP connection and the best route to that destination. Unless network redundancy is
provided implicitly in the destination addresses, the same adapter/line can be used for
all connections to the same neighbor. NonStop TCP/IPv6 (in either LNP or non-LNP
mode) and CIP can be configured with a redundancy feature at the adapter (or CLIM)
level called Ethernet failover. This feature allows you to configure two network
interfaces (IP addresses and their associated physical interfaces on the Ethernet
adapter) as a failover pair. Each network interface in this failover pair provides
complete, independent network connectivity in normal conditions and provides backup
connectivity for its brother during a failure. If one member of the failover pair fails, the
NonStop TCP/IPv6 or CIP subsystem automatically routes network traffic destined for
the failed interface over its failover brother. Failover in the CIP subsystem has some
restrictions that are not present in NonStop TCP/IPv6.
For more information on configuring Ethernet failover in NonStop TCP/IPv6, see the
TCP/IPv6 Configuration and Management Manual. For information about configuring
Ethernet failover in CIP, see the Cluster I/O Protocols (CIP) Configuration and
Management Manual.
Local Area Network (LAN) Driver and Interrupt Handlers (DIHs)
NonStop TCP/IP processes can interface to an IP network through the ServerNet LAN
Systems Access (SLSA) subsystem. The SLSA subsystem provides QIO-based driver
and interrupt handlers (DIHs) that allow NonStop TCP/IP processes to connect to a
LAN adapter. The SLSA subsystem is preconfigured and is started during the system-
load sequence.
For more information on the SLSA subsystem, see the LAN Configuration and
Management Manual.
Note. The CIP subsystem does not use the SLSA subsystem. See the Cluster I/O Protocols
(CIP) Configuration and Management Manual for more information on the CIP architecture and
migration considerations.